Process of preparing ethyl esters



V equation i Patented Nov. .11, 1930 UNITED STATES PATENT, oFFicE ARTHUR R. crew, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR TOTCARBIDE AND .CAR-

BON CHEMICALS .CORPORATION,

AQORPORATION OF NEW YORK PROCESS OF PREPARIlV G ETI-IYL ESTERS No Drawing. Application filed July 7,

This invention is a process of preparing ethyl esters by the use of diethyl sulphate.

Diethyl sulphate reactsrwith many metal salts producing by interchange of acid radicles the sulphate of the metal and the ethyl ester of the acid originally combined with the metal. Salts of alkali metals are usually used,'but not necessarily. Thus, with sodium benzoate the reaction is illustrated by the Nil/ 80 If it is attempted to carryout thereaction above by'heating together the reacting materials Without additions a very poor yield is obtained, possibly for the reason thatthe solved, but hydrolysis of the ester takes place to such a degree that the yield is still quite unsatisfactory.

Certain anhydrous solvents, such as benzene, avoid both the objections noted and give good yields of ester. They are unsatisfactory, however, partly because most-of the anhydrous solvents available are inflammable but principally because the ester produced canbe 1923. Serial No. 650,164.

ethyl benzoate then distilled ofi ma vacuum.

7 The yield was the ethyl "benzoate produced being of courserecovered together with salicylate, butyrate, etc. As already stated,'

salts of metals other than thealkalis may be used. j

I claim:

1. Processof preparing ethyl esterswhich comprises'causing di-ethyl sulphate to react with a sodium salt of an organic acid in the presence of a solvent, substantially free from water, comprising a preformed portionof the ester to be prepared. 7 1 s 2. Process of preparing ethyl benzoate which comprises causing di-ethyl sulphate to react with sodium benzoate in the presence of a. solvent comprising substantiallywater free ethyl benzoate. p

8. Process of preparing ethyl. benzoate which comprises causing di-ethyl sulphate to react with a metal benzoate in the presence of a solvent, substantially free from Water,"

comprising a preformed portion of ethyl ben-I 'zoate. 1 In testimony whereof, I afiix my signature.

ARTHUR R. (J DE.-

separated from the solvent. only with great difficulty.

According to my invention, I use. as a solvent for the reacting materials a quantity of the preformed ester, so that the product will-be obtained in a form unmixedwith extraneous substances. By such procedure the fire risk is often reduced as the ester is usually less inflammable than the other anhydrous solvents which are available. I

Carried out in the manner decribed, the

process is very simple. A specificfexample will serve to illustrate the procedure One mol (144 g.) of sodium benzoate was mixed with 150 g. of ethyl benzoate and to this mixture 1 was added an amount (7 7' g.) of diethyl sulg phate equivalent to the sodium benzoate. The complete mixture was heated to 145 C. for 5 hours under'a reflux condenser, and the 

